Troubleshooting & Best Practices

Common Issues

"Invalid sheet metal Brep" Error

Causes:

• Non-manifold geometry (holes, gaps)
• Inconsistent thickness
• Complex topology (bifurcations, T-junctions)
• Self-intersecting surfaces
• Check edges of bends

• Use Rhino's ShowEdges > Naked edges to find gaps
• Check for consistent thickness throughout
• Simplify geometry to valid sheet metal topology

Unrolling Gives Mirrored Results / Inconsistent Results

Causes:

• Root face selection
• Bend direction interpretation

• Try setting a dedicated root face index for consitency
• Try Back Side Up = true in Unroller
• Use Flip Bend Direction component
• Verify face normals point outward

Bend Detection Not Working

Causes:

• Bend radius too small/large
• Non-cylindrical bend surfaces
• Tolerance issues

• Check bend surfaces are truly cylindrical
• Adjust SheepTolerance
• Verify geometry represents valid sheet metal bends
• Use Display Sheet to see what was detected

Hem Detection Fails

Causes:

• Hem widths not provided to Non-Manifold To Sheet
• Geometry doesn't match hem pattern
• Tolerance issues

• Provide expected hem widths to HDW input
• Plugin looks for parallel edges at specified distances
• Verify geometry has proper hem structure (two parallel folds)
• Check thickness is consistent

Performance Issues

Causes:

• Large/complex geometry
• Merge Coplanar Faces enabled
• Thicken enabled in Unroller

• Simplify geometry where possible
• Disable Merge Coplanar Faces unless needed
• Disable Thicken unless 3D output required
• Components already use background tasks for optimization

Best Practices

Design Guidelines

1. Keep Geometry Simple

• Avoid bifurcations and T-junctions
• Maintain consistent thickness
• Use cylindrical surfaces for bends

• Add bend reliefs for complex intersections
• Use appropriate bend radii (typically ≥ thickness)
• Consider grain direction for directional materials

• Use Display Sheet immediately after creation
• Check Sheet Info for unexpected feature counts
• Verify bend directions match intent

Workflow Tips

1. Start Simple, Iterate

• Begin with basic K-factor (0.5)
• Test unrolling before adding complexity
• Gradually add advanced compensation if needed

• Display Sheet with different color modes
• Check bend groups for proper topology
• Verify text labels match expectations

• Save K-factor tables for materials
• Record bend relief settings for processes
• Export bend specifications for operators